The six-transmembrane epithelial antigen of prostate 2 (STEAP2) is a member of a family of metalloreductases identified as cell-surface antigens in prostate tissue. Similar to two other members of the STEAP family (STEAP 3 and STEAP4), STEAP2 promotes both iron and copper reduction. STEAP2 expression in transfected cells also correlated with iron or copper uptake, suggesting that the STEAP family of proteins may function to stimulate iron and copper uptake. STEAP2 is widely expressed in many tissues in the plasma membrane, but is most highly expressed in prostate. At least three isoforms of STEAP2 are known to exist.
